If you've been wondering what Audi will bring to the 2008 Paris motor show, the suspense is over. Meet the 2009 Audi S4, the performance-tuned variant of the revamped 2009 A4.

We'll start with what lies underhood. Never mind the TFSI badging that adorns the engine's plenum cover; there's not a turbocharger to be found in this engine bay. Instead, the 2009 S4 uses an all-new 3.0-liter supercharged V-6 with direct fuel injection. Sure, Audi could have changed the nomenclature, but would Kompressor-FSI have the same ring?

Detail-picky enthusiasts will move past the misnomer once they see the benefits of the V-6. Audi says the engine pumps out 333 hp, while torque - a good 324 lb-ft of it - is delivered between 2500 and 4850 rpm. Both figures compare admirably with the outgoing car's 4.2-liter V-8, which produced 340 hp and 302 lb-ft. Perhaps most impressive is the V-6's fuel economy. Audi says the engine drinks twenty-five percent less fuel, and returns an average 25 mpg in combined city and highway driving.

Predictably, Audi has mated the blown V-6 to its ubiquitous Quattro all-wheel-drive system, but there are a few new mechanical tricks. To start, there's the optional QuattroSport active rear differential. Activated by hammering the car through a corner, the differential shifts power to whichever wheel is on the outside. Audi claims doing this allows the axle to not only push the car through the corner, but also negates both over- and understeer.

Other options further the S4's performance credentials. Though a six-speed manual is standard, an all-new seven-speed S-tronic dual-clutch transmission is optional. So too is a variable-effort steering rack, but we're most interested in the new Audi Drive Select system. Available with any of the above options, Drive Select can modify steering, suspension, differential, and throttle responses based upon preset Comfort, Automatic, and Sport settings.